Online buzz: Fans of this monofloral New Zealand honey say it's the ticket to calming angry skin. They slather it on as a mask or apply it directly to zap particularly difficult blemishes.

Doctor's orders: It's legit: Manuka honey contains clinically proven antibacterial agents (among them an enzyme that releases hydrogen peroxide), and wound-care centers use medical-grade versions. Dermatologist Ellen Marmur, MD, recommends it as a targeted approach for perioral acne because it moisturizes and exfoliates instead of exacerbating flakiness; dermatologist Noëlle Sherber, MD, suggests it for stubborn, workout-related acne, the kind avid bikers might get around the helmet line, because it dissolves biofilm bacteria. Think of the ratings system the way you think of SPF: Look for a unique manuka factor (UMF) of 10 or higher.

Editor test drive: "I like experimenting with new products, so I wasn't put off by the honey's stickiness. It felt not unlike other thick facial masks and peels I've tried. I applied it all over and left it on for about an hour, three days in a row. Afterward, my skin felt soft and fresh, firm but not tight. One nasty spot even healed faster than usual. Flash forward a few months: I now carry manuka sachets with me wherever I go."

Online buzz: Proponents cleanse hair and skin by rinsing with what they lovingly call their "ACV."

Doctor's orders: "Apple cider vinegar removes residue and product buildup, acts as a natural detangler, and leaves hair softer and smoother," says dermatologist Fredric Brandt, MD. "It works to close up cuticles, helping strands reflect light, and fights dandruff." Bonus: ACV also functions as a skin toner to balance oil production and reduce inflammation, and its citric acid exfoliates. Brandt suggests diluting to a 1:2 ratio for skin or 1:1 for hair. But if you're worried about maintaining your color, Sherber warns this might not be for you.

Editor test drive: "I've used an apple cider vinegar rinse instead of conditioner once every two or three weeks for several months. You can shake it up in a spray bottle, but I mix mine with cold, filtered water in a plastic container, slowly pour it through my hair, and then rinse after five minutes. My hair feels lighter, bouncier, and shinier after I blow-dry on those days—and the scent doesn't linger. As a face toner, ACV was too intense for my supersensitive complexion."

Doctor's orders: According to Sherber, Pepto as a facial mask is "kind of a cool hack." It contains bismuth subsalicylate—a relative of acne-fighting super-ingredient salicylic acid, the beta hydroxy acid that unclogs pores and promotes skin turnover. "Pepto exfoliates and mattifies the skin, like a super-awesome pore strip," Marmur says, "but it could be too drying" for any but the most oily skin. Note: Don't try this if you're allergic to aspirin or if you've ever reacted badly to mineral makeup, as many contain bismuth.

Editor test drive: "The dried Pepto- Bismol on my face felt like Elmer's Glue—without the fun peeling part. I didn't notice any major pore minimization, but my blemishes seemed to shrink, so I'd definitely use it again as a spot treatment."

Doctor's orders: "There's no chemical reason why it would work, other than just as an abrasive," says Graham Forbes, DDS. That's how most whitening toothpastes act, gradually breaking down stains. "My main concern would be it's maybe too rough," which could lead to gum recession or enamel damage, especially if you follow up with vigorous postrinse brushing.

Editor test drive: "I've used whiteners in the past, but most made my teeth feel sensitive, so I was excited to try something natural. The charcoal powder was wildly messy: With black seeping from my mouth, I looked like the girl from The Ring, and I'm still finding traces of it on my tiles and towels. But after a somewhat silty gargle, my teeth were pretty sparkly."

Online buzz: Pool and beach bums champion vitamin A– and E–rich carrot derivatives to protect and pamper from head to toe.

Doctors' orders: Carrot oil might make for a nourishing leave-in conditioner, but don't count on it for UV protection. "It's like putting on baby oil: You could actually end up burning your scalp," Marmur says. "I recommend vitamin A to improve skin and hair, but you have to ingest it."

Editor test-drive: "The most common carrot oils have a soybean-oil base, which turned me off: They were too greasy for both skin and hair. Pure carrot seed oil, however, I love! I dab the bright orange oil on my cheeks when I need a little glow, or use it to smooth the ends of my hair. (It's too expensive to use all over.) But I definitely still get my SPF from other sources."

Online buzz: Coco addicts use it everywhere, morning and night—as a multipurpose moisturizer, as a cleansing balm, and even as a mouth rinse.

Doctors' orders: "Coconut oil is very emollient," says Sherber, citing a recent study that showed eczema-prone skin responded better to coconut oil than it did to mineral oil. Many oils perform well as a makeup remover, but according to Sherber, most of us shouldn't depend on the coconut variety as a cleanser. "I've seen patients follow coconut-oil-cleansing tips on Pinterest and come in with atrocious acne," she says. And though some coconut-derived products are advertised as having "natural sun protection," Sherber emphasizes that they're not reliable substitutes for moisturizers with a proven SPF rating, and that the reflective finish could intensify skin's exposure to UV rays. As far as a mouth rinse, Forbes says, "You're not going to hurt yourself, but you'll spend twice as long doing dental hygiene as you would otherwise."

Editor test-drive: "I'm hippie-dippie, so I'm not a stickler for requiring natural products to outperform their chemical counterparts. But I'm sad to say that coconut oil failed me. As a hair treatment, it was much too heavy for my wavy hair. And I can't recommend it as a face cleanser: It gunked up in my eyes when I used a dab to remove mascara, and didn't seem to fully erase my foundation and concealer, so I ended up needing to rewash—using so much extra water—each evening. I couldn't keep it in my mouth for longer than a minute before gagging, so no luck with the 'oil-pulling.' However, coconut oil does rock as body moisturizer: I put it on right after the shower, while my skin was still damp. My skin looked so soft and dewy, plus it smells amazing."